Welding guide



Oct. 4, 1949. B. W. WRIGHT WELDING Guin 2 Sheets-,Sheet .1

Filed Jan. zo, 1947 'Il l l Snventor Cittotneg B. W. WRIGHT WELDINGGUIDE Oct. 4, w49.

2 Sheets-Sheet 2 Filed Jan. 30, 1947 Zmncntor W W a 5 Femmina. 4, 1949WELDING GUIDE vBen W. Wright, Boonton, N. J., assigner to Curtiss-WrlghtCorporation, a corporation of Dela- Ware Application January 30, 1947,Serial No. 725,391

8 Claims. (Cl. 113-59) This invention concerns automatic weldingmachines and relates particularly to improvements for guiding anautomatic welding head along a welding path.

While this invention is not limited to the environment in which it ishere presented, the invention was developed for use in the manufactureof hollow steel propeller blades. In such propeller blades, convexthrust and camber plates are preformed, the plates then beingsuperimposed on one another after which weld metal is inlaid along theleading and trailing edges of the blade, integrally uniting the thrustand camber faces and forming portions of the leading and trailing bladeedges. Originally, these blades were welded by manual operations and asthe art progressed, automatic welding, such as submerged melt welding,was applied to the blades. It was found in using automatic welding thattemporary warping of the plates during the welding process presented aconsiderable problem since the welding head is usually guided by a camor guiding strip along a path representing the desired leading edge ortrailing edge planform. When warping of the blade occurred duringwelding, the blade moved relative to the controlled welding head path sothat the metal deposit was made erroneously.

It is an object of this invention to provide a guiding system for awelding head which will compensate for warping or displacement of thearticle being welded. It is a further object of the invention to providea flexible guide track for the control of the path of a welding head andfurther to provide a means for iexing the welding guide track inconformance with displacement of the article being welded. It is afurther object of the invention to provide a yieldable work holdingfixture whose yield will aiIect corrective movement of a welding headduring a welding operation.

A broader object of the invention is to provide a yieldable guide,associated with a work-piece, for guiding an instrumentality along theworkpiece, the instrumentality affecting certain changes in thecondition of the work-piece.

Further objects of the invention will become apparent in reading theannexed detailed description in connection with the drawings. Thedescription and drawings are to be considered only as exemplary of onemode of practicing the invention and are not to be construed as limitingits scope. Reference should be had to the appended claims for a specificdenition of the limits of the invention.

In the drawings, v

Fig. 1 is a plan of a work holdingv fixture and guide system for awelding head or other in strumentality used for changing the conditionof a work-piece, and

Fig. 2 is a section on the line 2-2 of Fig. 1, also showing a weldinghead and guide follower arrangement.

In both figures, wherein similar numbers indicate similar parts, 5represents a table upon which the work holding xture and guide systemare attached. Toward one corner of the table 5, a work -clamp B issecured which as shown holds the shank end 'I of a propeller blade 8.The tip end of the propeller blade is provided with a short extension 9engaging a dowel on a member I0 secured to the table 5. The propellerblade 8 as shown in Fig. 2 comprises a camber plate I2 and a thrustplate I4, the camber plate being rolled at its shank end to form theshank portion I and being so proled as at I5 that the thrust plate willt at its edges along the edges of the camber plate I2 and deilning weldjuncture paths 'I6 and 18. In laying up the plates I2 and I4 on the workholding xtures, the camber plate I2 rests upon a central support I8secured to y the table 5, and a removable spacer I8 is placed betweenthe plates I2 and 14 to hold them in their proper spaced relation. Onthe outer surface -of the thrust plate I4, a support member 20 issecured, whereby the plates I2 and I4 are secured to one another for thewelding process.

Along the leading edge 22 and along the trailingedge 24 of theprope1ler-blade8 are disposed a plurality of angle members 28 and v28respectively. Each angle member covers a short por- -tion of thepropeller blade span and is movably mounted as will be described so thatit may move' with the .propeller blade, should the latter move in thework holding fixture during the welding process. The portions of theangle members 26 and 28 which lie upon the table 5 are secured thereto,for movement relative to the table, by Z bars 30 secured as at 3l to thetable. Angle members 26 and 28 lying opposite one another across theblade are secured to one another by rods 32, through the medium of nuts34 engaging the member 26, and spring and nut arrangements 36 and 38engaging the members 28. By tightening up each nut 38, after assembly ofthe foregoing parts, eachfset of members 28 and 28 is resiliently urgedinto contact with the leading and trailing edges 22 and 24 of thepropeller blade, and both members 28 and 28 will 3 move transverselywith the blade should the latter Warp during the welding operation.

An extension of each rod 32, extending rightwardly as shown, is securedby nuts 40 to a channel element 42 resting upon the table 5, there beingone channel element 42 for each set of members 26 and 28, each channelmember 42 having a length substantially the same as the length of eachset of channel members 26 and 28. Thus, there will be a plurality ofchannel members 42 equal in number to the number of members 26 ormembers 28. Each channel member 42 will be movable independently of eachother channel member in accordance with the position of the controlmembers 26 and 28 secured to it. Each channel member 42 is provided witha central slot 44 and a bolt 46 or other suitable securing means passingthrough the slot 44 and engaging the table 6, securing the channelmember to the table but allowing sliding movement of the channel member.The end members 42 are bordered by fixed guides 41 secured to the table5.

Upon each channel member 42, a pair of clips 48 are adjustably securedas by capscrews 50, and the .upper side of each clip is formed with agroove 52. The clips 48 are adjustable on the bolts 58 so that they maybe turned or moved back and forth'along the channels 42. Within thesuccession of grooves 52 ofthe several clips 48, a leading edge guide strip 54 and a trailing edge guide strip 56 is laid, these guide stripsbeing curved to conform to the desired weld paths 16 and 'I8 along theleading edge and trailing edge of the propeller blade 8.

Preferably, when a work setup is being made, the members 26 and 28 willbe secured so that they lie against the leading and trailing edges ofthe blade 8, and then the members 42 will be adjusted to align with oneanother as shown in Fig. 1. When so located, the clips 48 and the guidestrips or tracks 54 and 56 will be adjusted to conform to the desiredweld paths I6 and 18 along the leading and trailing edges of thepropeller blade.

As shown in Fig. 2, a Welding head 58 is secured to a cross beam 60slidably passing through a block 62, the right hand end of the crossbeam 66 carrying a member 64 to which a roller pivot head 66 ispivotally secured at 66, the head 66 in turn, carrying guide followingrollers 'I0 and 12. The block 62 carries rollers .or other suitablemeans engaging over head rods 14 running longitudinally over the middleof the table 5. By this construction, the rollers'l and l2 by theirengagement with track 54 or 56 control the transverse movement of thewelding head 58 as the block 62 is moved along the supports 14.

Assuming that a welding pass may have been started on the blade assemblyfrom a point near the shank, welding will progress along the path 16,controlled by the guide track 54. As the welding progresses thetemperature of the blade assembly is elevated materially along one edge,causing its material to expand thus temporarily warping the blade to theleft of its normal position as controlled by the holding member 6 andI0. Without compensation, the welding head would then deviate from thedesired path 'I6 but with the compensation by means of the apparatusdescribed, the guide track 54 is warped in conformance with the warpageof the blade because the guide tracks and channels 42 are moved toconform to the position of the blade edge against which rest the guidecontrolling members 26. As

head movable longitudinally of said laterally with said members eachsuccessive stage of welding is reached, the above compensation willoccur and upon cooling of any blade zone it may return to its normalposition with concurrent return of the guide track 54 to its normalposition.

When the welding pass is made along the trailing edge of the blade usingthe guide track 56, the same sort of displacement will occur in responseto blade movement; in this instance the blade will tend to warp towardthe right and the guide track 56 for the trailing edge will likewisemove toward the right, controlling the position of the welding head 58so that it will lie at all times along the proper welding path 18.

The compensating structure above described is particularly applicable toautomatic welding operations, either on propellerblades or on otherarticles which are subject to warpage during welding processing. Acompensating arrangement of the character described might also be usedfor operations on work-pieces which do not involve Welding but rather,involve brazing or other heating, or certain types vof machineprocesses.

In effect, the invention provides means for guiding an instrumentalityaccomplishing an operation on a work-piece in response to the instant orlocal position of an increment of the work-piece itself, rather thanguiding the instrumentality from a fixed or constant datum.

Though but a single embodiment of the invention has been illustrated anddescribed, it is to be understood that changes may be made withoutdeparting from the spirit or scope thereof, as will be apparent to thoseskilled in the art. Reference should be had to the appended claims for adenition of the limits of the invention.

What is claimed is:

1. A welding fixture for the welding of elongated articles near theiredges comprising means to hold the article, a plurality of substantiallysimilar laterally movable members spaced along the article and eachconstrained to contact the article edge at different portions thereof,said members being individually laterally movable with the articleduring welding therealong upon temporary warping of the article at thezone of welding due to temperature changes, a fiexible guide trackspaced from the article edge and conformed to the desired weld path atsaid edge, means securing successive points along said track tosuccessive members, whereby said guide track Ilexes in conformance withmovements of said edge and members during welding, a welding article forwelding feed, and means for moving said head laterally, engaging saidguide track, to constrain said head to movement along the edge of saidarticle concurrently with longitudinal head feed movement.

2. A fixture for an elongated article to be welded wherein the articleis subject to Warping during a welding pass along an edge thereof andwherein an edge of the article comprises the datum from which the weldpath is established, comprising means to hold the article, a pluralityof laterally movable members spaced along and each in contact with adifferent portion of said edge, a guide track secured to and movable andhaving the general configuration of said edge, and a welding headmovable both longitudinally and laterally relative to said articlehaving guide track engaging means to control the movement of said headlaterally relative to the edge of said article as said head is movedlongitudinally along said edge.

3. A fixture for an elongated article to be welded wherein the articleis subject to warping during a welding pass, comprising an articleholding means, said article having an edge portion adjacent the weldpath, a plurality of means spaced along and contacting said portion andmovable laterally with the article during warping, a welding headcontrolled in its lateral position relative to the article by saidplurality of means, and means to support said head for longitudinal feedmovement along said article.

4. A fixture for an elongated article to be welded wherein the articlemay move laterally during a longitudinal welding pass under theinfluence of thermal expansion and contraction, including means to holdsaid article, a plurality of guide members engaging the article atdifferent parts therealong adjacent the weld path and movable laterallywith respective parts during a welding pass, a welding head movablerelative to the article along a weld path, and means to adjust said headlaterally in its movement along said path in accordance with movementsof said guide members.

5. A xture for an article to be welded wherein the article may movelaterally during a longitudinal welding pass under the inuence ofthermal expansion and contraction, including means to hold said article,a plurality of guide members engaging the article at different partsthereof and movable laterally with respective parts during a weldingpass, a welding head movable relative to the article along a weld path,and means to adjust said head laterally in its movement along said pathin accordance with movements of said guide members said adjusting meanscomprising a flexible track secured to isaid members, along said trackand rigid with the welding head.

6. A fixture for an article to be welded wherein the article may movelaterally during a longitudinal welding pass under the inuence ofthermal expansion and contraction, including means to hold said article,a plurality of guide members engaging the article at different partsthereof and movable laterally with respective parts during a weldingpass, a welding head movable relative to the article along a weld path,and means to adjust said head laterally in its moveand a track followermovable ment along said path in accordance with movements of said guidemembers. said adjusting means comprising a flexible track secured tosaid members, and a track follower movable along said track and rigidwith the welding head said track being laterally spaced from thearticle.

7. In a welding fixture for elongated propeller blade components, meansto support said components, a plurality of members spaced along andengaging different parts of a lateral edge of one said component andconstrained to'move therewith, a flexible guide track generallyconformed to the desired weld path along said components,` means tosecure successive points along said track to successive members, and awelding head movable along the components, and movable laterallythereof, having a portion engaging said track to enforce the lateralmovement and having a portion for depositing weld metal on saidcomponents in the vicinity of their edges as the head is moved alongsaid components.

8. In a work holding fixture for an elongated workpiece whose conditionis to be changed and which, during and by the change of condition, ismoved transiently, means to support the workpiece for said transientmovement, a plurality of members contacting the workpiece at differentpoints therealong and movable with said workpiece, a flexible trackadjacent said workpiece having spaced-apart portions thereof secured torespective said members, said track being conformed to a work-path likethe work-path desired on the workpiece, and mechanism movable along andlaterally over said workpiece having a portion engaging andposition-controlled laterally by said track and having another portionlaterally xedly spaced from said first portion, for effecting acondition change in the workpiece, and means to move said mechanismalong said track and workpiece.

BEN W. WRIGHT.

REFERENCES CITED The following references are of record in th file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,554,101 Krebs et al. Sept. 15,1925 2,305,167 Kasper Dec. 15, 1942 2,403,514 Franzen July 9, 1946

